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安定区退耕还林工程的生态效益评价 被引量:21
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作者 周文渊 赵岩 +2 位作者 郭建英 孙保平 杨越 《中国农学通报》 CSCD 北大核心 2009年第20期115-120,共6页
生态效益的评价和核算对评价林业生态工程的建设效果至关重要。文章以截止2008年底安定区退耕工程取得的成绩为基础,估算了增加森林在涵养水源、保护土壤、固碳制氧、净化环境、改善小气候、保护生物多样性等方面在退耕期间所产生的生... 生态效益的评价和核算对评价林业生态工程的建设效果至关重要。文章以截止2008年底安定区退耕工程取得的成绩为基础,估算了增加森林在涵养水源、保护土壤、固碳制氧、净化环境、改善小气候、保护生物多样性等方面在退耕期间所产生的生态效益。结果表明:安定区退耕还林工程取得了巨大的生态效益,核算后的总生态价值约为260905.12万元,保护水资源价值为74130.60万元,保育土壤价值为33426.29万元,固碳制氧价值68122.43万元,净化环境价值为2928.06万元,改善小气候价值10291.34万元,保护生物多样性价值72006.4万元。研究结果可为黄土区退耕还林工程建设效益评价提供参考。 展开更多
关键词 安定区 退耕还林 生态效益 经济价值
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Research on Flood Control Design Based on Joint Distribution of Flood Levels and Flood Peak Discharges
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作者 Zishen CHEN Qiang HUANG Chunqiong HUANG 《Meteorological and Environmental Research》 CAS 2020年第6期73-77,共5页
The return level of the joint distribution of flood levels and flood peak discharges was analyzed by Archimedean Gumbel-Hougaard copula and Kendall distribution functions.Using the annual maximum level(H)and discharge... The return level of the joint distribution of flood levels and flood peak discharges was analyzed by Archimedean Gumbel-Hougaard copula and Kendall distribution functions.Using the annual maximum level(H)and discharge(Q)of flood peak at Boluo Hydrologic Station in the Dongjiang River in last 56 years,the"OR"return period,"AND"return period and Kendall return period of their joint distribution and the most likely design flood value were calculated.The main conclusions of this study can be summarized as follows:the Kendall return period can more accurately reflect the risk rate of the combination of flood elements,relative to"OR"return period and"AND"return period.The design value of univariate flood element based on the current specification can meet the design standard.While the design value calculated according to"OR"return period was on the high side,and the design value calculated by the"AND"return period was on low side.Based on the principle of maximum probability,the calculated design value of Kendall return period under the different combinations of flood peak discharge and water level can provide new options for flood control project safety and risk management. 展开更多
关键词 Flood risk assessment "OR"return period "AND"return period Kendall return period Design flood return level
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